A wide variety of audio only and audio/video components is presently commercially available thus giving a user a number of interconnection possibilities to create a home entertainment system personalized to his own particular desires.
One method for interconnection of these various components is to manually connect cables between those components which are presently to be used and to manually change the cable connections when it is desired to use other components. One disadvantage of this method is that the cables must be re-arranged each time it is desired to change the system configuration. Moreover, a manual wiring change requires some knowledge of the individual component details, something a child or a guest may not possess.
An alternative to manually rewiring a component video system for changing the system configuration is described by Strammello, Jr. in U.S. Pat No. 4,400,735 entitled MULTI-COMPONENT VIDEO SYSTEM CONTROLLER. In this system, manually operated pushbutton selectors provide D.C. control voltages to a matrix of electronic RF switches to permit the simultaneous viewing and recording of video signals from various sources in different combinations. Notwithstanding its advantages, the manual RF switching system lacks the facility for interconnecting audio-only devices or baseband video devices. Moreover, overall system control requires operation of the controls of each individual device plus the manual control for the RF switch matrix.
A two-component TV-VCR system featuring RF and baseband switching controlled by a common remote control is described by Kozakai et al. in U.S. Pat. No. 4,527,204 entitled REMOTE CONTROL SYSTEM. The TV receiver and the VCR each include respective remote control receivers for controlling RF and baseband video switching as well as the normal operating modes of the TV and VCR. A single hand-held remote control unit controls all operational aspects of both devices as well as selecting desired interconnections. Such a system, however, is not readily adaptable for expansion to include additional components and has no provision for inclusion of audio-only devices in a comprehensive unified home entertainment system.
It has been recognized that a large number of audio/video and audio-only devices may be combined in a unified home entertainment system by providing a central control unit coupled via a digital data bus to individual device of the system. An example of such a system is described by B. W. Beyers, Jr. in U.S. Pat. No. 4,581,645 entitled DISTRIBUTED SWITCHED COMPONENT AUDIO/VIDEO SYSTEM. Other examples include U.S. Pat. No. 4,337,480 of Bourassin et al. entitled, DYNAMIC AUDIO-VIDEO INTERCONNECTION SYSTEM and U.S. Pat. No. 4,488,179 of Kruger et al. entitled TELEVISION VIEWING CENTER SYSTEM. R. A. Pitsch describes a bus-oriented system in an article entitled "Dimensia: The Next Dimension of Sight and Sound" published in RCA Engineer, July/August edition, 1985, at pp.66-70. In the described system the control bus provides two-way communication between a central controller and a plurality of individual device controllers. By this feature a user may transmit a status request and receive a response (displayed on the screen of his TV receiver) that gives the status (e.g., play, pause, etc.) of any selected device in his system. The user may also transmit commands via the two-way data bus to select and control the "status" or operating mode of individual audio and video peripheral devices connected to the bus.
It is known that one may provide timed control of a VCR, for example, by including a clock circuit in the VCR for initiating functions such as recording time periods and channel selection at times determined by the clock. It has been recognized by Brugliera et al. in U.S. Pat. No. 4,631,601 entitled TIME PROGRAMMABLE CONTROL SYSTEM FOR A CONVERTER/VCR SYSTEM that an additional clock is needed for timed operation of a VCR from a cable TV converter. This is because cable converters manually provide an output signal on channel 3 or 4. Accordingly, to change channels at a programmed time an additional clock is necessary for the converter to provide channel selection with the recorder clock being used to select the converter output channel and recording times. In the Brugliera et al. system the extra clock is included in a remote control transmitter which supplies command signals to the cable decoder on a user determined time schedule for controlling the converter time and channel selection operation to correspond to the recording time schedule established for the VCR. Brugliera et al. caution that in their two clock system the user must take care that the clock in the VCR and the converter clock are in agreement. A lack of clock synchronization will result in a spoiled or missed recording.